Nim vs Pony

There are generics, templates, macros in Nim. They can allow you to write new DSL for your application, or avoid all boilerplate stuff.

Checks your code at compile time.

With built-in "unittest" module you can create test with a very readable code.

Nim has "asyncdispatch" module, which allows you to write async applications.

Nim has a built-in VM, which executes macros and some other code at compile time. For example, you can check if you're on Windows, and Nim will generate code only for it.

The same code can be used for web, server, desktop and mobile.

Nim has a lot of common with Python in terms of syntax. Indentation-based syntax, for/while loops.

Imperative, OOP, functional programming in one language.

You can use Nim with any language that can be interfaced with C. There's a tool which helps you to create new C and C++ bindings for Nim - c2nim.
Also, you can use Nim with Objective C or even JavaScript (if you're compiling for these backends).

You don't need to deal with all those manual memory allocations, Nim can take care of it. But also you can use another GC, or tweak it for your real-time application or a game.

You only need to specify types in your procedures and objects - you don't need to specify type when you're creating a new variable (unless you're creating it without initialization).

You can use unicode names for variables, there is "unicode" module for operations with unicode.

writeLine(stdout, "hello") can be written as stdout.writeLine("hello")
proc add(a: int): int = a + 5 can be used like 6.add.echo or 6.add().echo()

The unique type system allows the compiler to automatically schedule actors on threads, giving you reliable concurrency for free.

Because of its capabilities secure type system, provided you don't use the C FFI, references will never be stale, race conditions are effectively impossible, deadlocks don't happen because locks and mutexes are never needed, and processes never crash because all exceptions must be handled. (Barring compiler bugs or external memory corruption, of course.) Pony programs can still lock up due to infinite loops, like any Turing-complete language.

Compiles to native code, and features an intelligent garbage collector that takes advantage of the actor architecture to get essentially free garbage collection.

Calling low-level C functions is as simple as use "lib:clibrary" and @c_function_name[return_type](parameter:type). Linking C to Pony libraries is just as easy, as the Pony compiler will generate appropriate header files.